For the things that are 1:1 comparable, the Borg abstraction leaks in pretty much the same places as the Kubernetes abstraction. In slightly different ways. The "kubernetes abstraction" spans a larger space than the Borg abstraction does (note, I count "Chubby" and "GSLB" as "not Borg"), so there are more abstraction leaks as a whole in Kubernetes.

Source, I was a Google SRE for 5 years (Ads, Traffic). I ran the in-house kubernetes clusters at a company for 3 years (so, no, no hosted kubernetes, we stood them up either on pretty naked VMs or bare metal).